3. Continue adding drops until the shade resembles that of real blood (always err on the side of adding less, as it's easier to add more).

4. Add a small amount of blue or green food colouring to achieve a more realistic shade (arterial blood is bright red and venous blood is a dark maroon).

5. Add a thickener. Suitable thickeners include:

Dry thickener: Add sifted flour or corn starch to your mixture, and whisk or stir it gently until smooth. If small lumps form, wait about a minute and the lumps will float to the top where you can remove them easily.

Wet thickener: Stir in thick chocolate syrup until the desired consistency is reached.Heat but don't boil.

1. Dissolve 1-2 teaspoons of gelatin in 2/3 cup hot water.

2. Beat with an egg beater to remove the lumps.

3. Pour gelatin mixture into hot blood. Leave to cool.

4. Roll out a sheet of cling film to the size of blood splatter you require. Pour gelatin on glad wrap and leave to set.